Refrigerating apparatus



Dec. 20, 1932-. J, R K|| EN 1,891,232

REFRIGERATING APPARATUS Filed Feb. 19, 1930 2 snee'-sheet 1 xxm xxxx IN VEN TOR @Zig- BY 5;?2

//S A TTORNEYS.

De@ 20, i932. V.,1. n KILLEN 1,891,232A

REFRIGERA'LING APPARATUS Filed Feb. 19, 1930 2 Sheets-Sheet 2,

/5 A TTORNEYS,

Bww ML, y

Patented Dec.' 20, 1932 Nrrao sTA'rEsf PMENTA oFFlfc-a f REFRIGEBATING APPARATUS KILLER', OF DAYTON, OHIO, ASSIGNOR T0 FRIGIDAIRE CORPORATION, OF

DAYTON, OHIO, A CORPORATION OF DELAWARE v.application niet February 19, 1930. seriai No. 429,788.

This invention relates to improvements in refrigeratin'g apparatus and particularly to improvements in evaporators or refrigerating elements used in mechanically refrigerated cabinets.

It is an object of the present invention to provide an improved refrigerating element or evaporator which can be used in refrigerators of the type in which the cooling section or compartment is relatively `lojng and narrow such as the chambers of large commercial storage cabinets.

` -More particularly it is an object of the inf vention to increase the efficiency by insuring is the circulation of refrigerant in a relatively long and narrow refrigerating element. In carrying out the above object it is a further` object to providea plurality of ducts or plpes adapted to interconnect spaced headers and 2o to provide cross-over meansV between the headers whereby; the path of flow of the evaporated refrigerant is reduced.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the j accompanying drawings, wherein a preferred form of the present invention is clearlyj shown. A. f

In the drawings: Fig. 1 is a vertical cross sectional view of a cold storage cabinet having a cooling unit constructed according to thepresent invention installed therein Fig. 2 ,is a top view of the improved refrigerating element; l

Fig. 3 isa front view of the improvedrefrigerating element shown in Fig. 2;'.

Fig. 4 shows a modified form of refrigerating element embodying features of the present invention; and

Fig. 5 is an enlarged sectional view through the refrigerating element taken von the line 5-5 of Fig. 2 but `having parts of the tubes broken away. l l

Horizontal evaporators of the type having a chamber or header connected by a plurality of long refrigerant ex ansion pipes or ducts have been found ine cient for cooling errculating air if extended beyond a certain length. In relatively long evaporators of thls construction the refrigerant in the central portions .of the ducts'becomes oil-logged or dormant. This dormant condition of the refrigerant, in these portions of the ducts is caused by the great distance which the refrigerant gas is required to travel or flow before it reaches an open path, or a path not flooded or obstructed by liquid refrigerant, which leads 'to the outlet of the evaporator. The great distance that the refrigerant gas in the central portion of the ducts is required to travel causes liquid refrigerant, in the tubes, nearest the gas outlet or outlets of the ducts, to boil or evaporate rapidly. In

order to provide the required refrigeration the ends of the evaporator must be cooled to a very low temperature. When this condition exists within the evaporator, the entire refrigerating system as well as the evaporator 'is ineicient-and produces a non-uniform air 70 a cooling compartment 12 and a storage com- 85 partment 13 by a baille 14 spaced from and located under the evaporator 10. The baille 14 is also spaced from the front and rear walls of the cabinet 11 so as to provide fiues or passages for the circulation, of air from compartment 13 to and over the evaporator l 10 located in the cooling compartment 12. The baille 14 is disposed at an angle and is provided with a gutter 15 at its lower edge which directs moisture, during defrosting of l the evaporator 10, to the drain pipe 16 which leads to the exterior of the 'cabinet A plurality of doors 17 hinged to the front wall `of cabinet 11 permit access to the storage com-4 partment 13. In the particular embodiment gas return pipe 19, to a mechanical refrigerbe observe ating unit (not shown) of any suitableconstruction.

Referrin in detail to the drawings it will that the improved refrigerating element or evaporator 10 comprises a main :header 20 and an auxiliary or additional header 21. A cross-over connection/or header ,22 is disposed between the headers 20 and 21.

The header 22 and the headers 20 and 21 are connected by a duct system composed of a plurality of individual pipes 23. lIt is one of the features of the invention to so arrange these ducts that some are below7 the liquid refrigerant level and some above the liquid level maintained in the evaporator. Such arrangement of the ducts provides a relativeopen path to the outlet of the evaporator l i throughout the length thereof to permit refri erant gas to iow freely.

s above statedliquid refrigerant is present in evaporator 10 and is covered with a thin layer of oil 24 which oil is circulated to the evaporator along with liquid refrigerant during 'operation ofthe refrigerating mechanical unit. The level of `liquid refrigerant in the evaporator 10 is controlled by any suitable float valve mechanism 25 and is maintained substantially at'the height indicated at 26. In the particular type of evaporator illustrated, by way of example, the liquid refrigerant inlet to the evaporator is indicated by 18a and the suction or outlet by 19a. The liquid refrigerant will pass throughthe ducts 23 connecting the header 22 and the heads 20 and 21 and will lie in the header 21 and .header 22y at substantially the same level as in the header 2O which houses the float valve mechanism 25.

The cross over means or header 22 may be formed of two cup members and 31 (see Fig. 5) having apertures in their end walls for receiving the ends 32 of the pipes `23 which are soldered to the header 22. The cup members 30 and 31 are each provided with an outwardly turned flange 34 which flanges are clamped between clamping rings 35 b bolts 36. A gasket 37 located between the anges 34 and the rings 35 seal the 'oint in the tank 22 from refrigerant leaks. ach of the headers 20 and 2l are provided with a plurality of holes in one side wall thereof. The upper and lower rows of the holes 40 have a cover member 41 secured to the boiler in any suitable manner such as by welding thereto. Each cover member 41 is provided with holes 42 which receive the' ends 43 of pipes 23 which communicate withkthe interior of the headers through the holes 40 provided therein. The header 22 being detachable in the manner describedpermits longer or shorter rear sections to be attached to the section of the evaporator containing the float valve mechanism for varying the length of the evaporator.

In Fig. 4 I haveshown a modified form of the evaporator in which the header 22 located between'the headers 20 and 21 is not detachable. The pipes 23 extend from the rear wall of the main horizontal header 20 so as to'provide a very narrow evaporator. This narrow evaporator may be desirable for use in amore shallow compartment than that in which my preferred type is used. However the features of my invention are also im ortant in this type of evaporator.

n order to facilitate the exchange of heat between the air and the ducts or pipes 23 of the refrigerating element 10 the connecting ducts are provided with fins 45.' These iins are disposed transverse to the longitudinal axis of the element, that is, substantially parallel to the side walls of the headers in the evaporator of the preferred type .l and substantially parallel to the end walls of the headers in the evaporator of themodiied form. The fins 45 are spaced apart all along the length of the connecting ducts 23. These fins are preferably forced'on the tubes or ducts 23 and secured in place by means of' small tubulars or flanges 46 punched out of the fins and, if desired, the fins may be soldered to the ducts to insure good thermal contact.

The intermediate header 22 of the improved refrigerating element permits the escape of refrlgerant gas from the lower liquid refrigerant ducts to the gas return ducts leading to header 2O.- In this manner the ebullition throughout the entire length of the ducts is suflicient to prevent oil-logging of the lower liquid refrigerant ducts.

From the foregoing -it is apparent that I have provided for the manufacture of relatively long narrow evaporators the parts of which are all substantially in the same horizontal plane and in which an efficient circulation ofrefrigerant will occur. Furthern more my improved' evaporator will be mamtained at substantiall the same temperature throughout its lengt thus insurin a uniform circulation of air cooled by suc evaporator while at the same time effecting an efficient return of lubricant from the evaporator to the compressor of they mechanicall refrigerating unit.

`While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A horizontally elongated evaporator of a refrigerating system comprising in combination, a header having an inlet and an outlet adapted to be connected to a refrigerant circulating means, a second header spaced from the frstheader, a plurality of ducts in-' llO Y ing a gas space, a plurality of ducts interconl0 from the duct disposedbelow the refrigerant level and the duct above the refrigerant level, said headers and ducts being substantially within the same horizontal plane.

2. A horizontally elongated evaporator of a refrigerating system comprising in combination, a header having an inlet and an outlet adapted to be connected to a refrigerant circulating means, a second header spaced from the first header, said headers containing a quantity of liquid refrigerant and havnecting said headers, a plurality of ducts extending outwardly from said second header, certain of said ducts being disposed above the liquid refrigerant level in said evaporator and certain other of said ducts being disposed below the liquid level, and a third header connected with the ends of said second mentioned ducts.

3. A horizontally elongated evaporator of a refrigerating system comprising in combination, a header having an inlet and an outlet adapted to be connected to a refrigerant circulating means, a second header spaced from the first header, said headers containing a quantity of liquid refrigerant and having a gas space, a plurality of ducts interconnecting said headers, a plurality of ducts extending outwardly from said second header, certain of said ducts .being disposed above the liquid refrigerant level in said evaporator and certain other of said ducts being disposed vbelow the liquid level, and a third header connected with the ends of said second mentioned ducts, all of said ducts and said third mentioned header being within the height of vthe walls of said first and second mentioned headers.

. 4. A horizontally elongated evaporator of a refrigerating system comprising in combination, a header adapted to contain liquid refrigerant, means within said header for preventing liquid from rising-above a certain level, a second header spaced from said first mentioned header, a plurality of duct means connecting both of said headers, some of said ,plurality of duct means being disposed above the liquid refrigerant level and `some other of said plurality of duct means being disposed below the liquid level, cross-over meansbetween said headers and connected with all of said duct means extending between said headers.

5. A horizontally elongated evaporator of a refrigerating system comprising in combination, a header adapted to contain li uid refrigerant, means within said header or preventing liquid from rising above a certain level, a second header spaced from said first mentioned header, a plurality of duct means connecting both of said headers, some of said plurality of duct meansvbeing'disposed above the liquid refrigerant level and some other of said plurality of duct means being disposed below the liquid level, cross-over means between said headers and connected with all of said ductmeans extending between said headers, said cross-over means and said duct means being substantially within the same horizontal plane of' said headers.

6. A, horizontally elongated evaporator of a refrigerating system comprising in combination, a header adapted to contain liquid refrigerant, means within said header for preventing liquid from rising above a certain level, a second header spaced from said first mentioned header, duct means connectsecond mentioned headers and connected with" said duct means, said third mentioned header and said duct means being substantially within the height of said first and second mentioned headers.

7 A relatively long narrow evaporator of a refrigerating'system comprising in combination, a header` adapted to contain liquid refrigerant, means within said fheader for preventing liquid from rising above a certain level, duct means extending outwardly from a wall of said header, saidduct means connected with a second header, duct means extending from said second header in the same direction as said first mentioned duct means., certain of said duct'means being disposed above the liquid refrigerant level in said evaporator and certain other of said duct means being disposed below the liquid level, and a third header connecting the ends of said second mentioned duct means.

8. A relatively long narrowv evaporator of a refrigerating system comprising in combination,l a header adapted to contain liquid refrigerant, means within said header for preventing liquid from rising above a certain level, duct means extending outwardly from a wall of said header, said duct means connected with a second header, duct means eX- tending from said second header in the same direction as said first mentioned duct means, certain of said 'duct means being disposed above the liquid refrigerant level in said evaporator and certain other of said duct means being disposed below the liquid level,

its

header heihg'wihhin the height;J of Said erst and second mentioned headers.

9. A horizontally elongated evaporator l' comprising a tube section forming the major heat transfer surface of the evaporator in contact with the liquid refrigerant, said section including a lurality of long, slender"v and horizontally isposed liquid refrigerant conveying tubes, a headerV for y supplying liquid refrigerant to thev tube section, said header having a gasspace, a plurality of gas conduits connected with. the header and extending longitudinally of the tube section, and cross-over duct means interposed between the ends, of the section and connected with all of said tubes and wlth all of said pluralit of gas conduits for conveying vaporized refiigerant from a plurality of said tubes to said gas conduits. p

In testimony whereof I hereto ailix my signature.

JAMES R. KILLEN.

plurality of liquid refrigerant' 

